Leachate and Standing Water Characteristics of Dairy Manure and Bottom Ash Blends

Abstract

A column study was conducted to evaluate three blends of bottom ash (BA) and composted dairy manure (CM), namely B1 (95:5%), B2 (90:10%), and B3 (80:20%) for use as a soil amendment material. Samples from standing water (top) and leachate (bottom) were collected at weekly intervals to evaluate the effects of different blend ratios and time on chemical and physical properties. Generally, a higher CM content in blends resulted in higher leachate concentrations for total solids (TS), total dissolved solids (TDS), total volatile solids (TVS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), nitrate (NO3-N), ammonium (NH4-N), phosphorus (P), and potassium (K). Concentrations of nearly all chemicals were lower in standing water (top) compared to leachate (bottom) for the blends. Standing water for alkaline blends remained below the USEPA drinking water standard for TDS for the entire duration of the study. Leachate for blends B1 and B2 was below the USEPA drinking water standard for NO3-N while standing water for all blends was well below the standard for the entire duration of the study. P concentrations were low in leachate and non-detectable in standing water for all blends. Based on these findings, it is concluded that B1 (95:5%) and B2 (90:10%) may be considered as a soil amendment substitute.